The term “spectrometry” encompasses various analytical methods for determining the makeup of various chemical compounds and mixtures of compounds. One type of spectrometry is mass spectrometry (MS), which measures the mass-to-charge ratio and abundance of gas phase ions in a sample. In particular, time-of-flight (TOF) mass spectrometry is a useful method for evaluating ions based on a time-separating measurement.
In mass spectrometry, a sample is ionized (e.g., by bombarding it with electrons or by exposing it to high intensity laser light) to generate electrically charged fragments (“ions”) of the compounds therein. The charged fragments are then separated according to their mass-charge ratio (m/z). Typically, the separation is conducted by accelerating the ions and subjecting them to an electric or magnetic field. For example, in an electric field, ions accelerate in the direction opposite to their polarities (e.g., positive ions accelerate away from the positive electrode).
Typically, after formation and acceleration of ions, the ions are introduced into a “flight tube” wherein different ions can be separated. The flight tube generally is under vacuum, without an electric field. All ions are passed into the flight tube with the same kinetic energy. It is understood that a sample of different ions, moving in the same direction and having substantially comparable kinetic energies, but having varied masses, will have a corresponding distribution of velocities, in which velocity is inversely proportional to the square root of m/z. Light weight ions with the same amount of energy will travel faster than heavier ions. The ions thus travel at different velocities down the flight tube, with ions of identical mass and charge travelling together in “packets,” and the packets becoming better separated from one another as they travel down the flight tube.
The ion packets are then detected, with each packet giving rise to a mass peak. The results are typically displayed as spectra of the relative abundance of detected ions as a function of the mass-to-charge ratio of the ion packets. The atoms or molecules in the sample can then be identified by correlating known masses to the identified masses or through a characteristic fragmentation pattern. Various additional and modified features can be incorporated within spectrophotometers. For example, one or more focusing elements and/or reflectors can be provided to modify the properties of the instrument.
One exemplary use for such instruments is in analyzing smoking products, flavor generators and medicinal inhalers that utilize electrical energy to heat and vaporize volatile materials, or otherwise attempt to provide many of the sensations of smoking, without burning tobacco to any significant degree. See, for example, the various types of aerosol generation devices described, discussed, or referenced in U.S. Pat. No. 7,726,320 to Robinson et al., U.S. patent application Ser. No. 13/826,929, filed Mar. 14, 2013, to Ampolini et al., Ser. No. 14/011,992, filed Aug. 28, 2013, to Davis et al., and Ser. No. 14/170,838, filed Feb. 3, 2014, to Bless et al.; which are incorporated herein by reference in their entireties.
In this regard, certain tobacco products that have employed electrical energy to produce heat for smoke or aerosol formation, and in particular, certain products that have been referred to as electronic cigarette products, have become commercially available throughout the world. Representative products that resemble many of the attributes of traditional types of cigarettes, cigars or pipes have been marketed as ACCORD® by Philip Morris Incorporated; ALPHA™ JOYE 510™ and M4™ by InnoVapor LLC; CIRRUS™ and FLING™ by White Cloud Cigarettes; BLU™ by Lorillard Technologies, Inc.; COHITA™, COLIBRI™, ELITE CLASSIC™, MAGNUM™, PHANTOM™ and SENSE™ by Epuffer® International Inc.; DUOPRO™, STORM™ and VAPORKING® by Electronic Cigarettes, Inc.; EGAR™ by Egar Australia; eGo-C™ and eGo-T™ by Joyetech; ELUSION™ by Elusion UK Ltd; EONSMOKE® by Eonsmoke LLC; FIN™ by FIN Branding Group, LLC; SMOKE® by Green Smoke Inc. USA; GREENARETTE™ by Greenarette LLC; HALLIGAN™, HENDU™, JET™, MAXXQ™, PINK™ and PITBULL™ by Smoke Stik®; HEATBAR™ by Philip Morris International, Inc.; HYDRO IMPERIAL™ and LXE™ from Crown7; LOGIC™ and THE CUBAN™ by LOGIC Technology; LUCI® by Luciano Smokes Inc.; METRO® by Nicotek, LLC; NJOY® and ONEJOY™ by Sottera, Inc.; NO. 7™ by SS Choice LLC; PREMIUM ELECTRONIC CIGARETTE™ by PremiumEstore LLC; RAPP E-MYSTICK™ by Ruyan America, Inc.; RED DRAGON™ by Red Dragon Products, LLC; RUYAN® by Ruyan Group (Holdings) Ltd.; SF® by Smoker Friendly International, LLC; GREEN SMART SMOKER® by The Smart Smoking Electronic Cigarette Company Ltd.; SMOKE ASSIST® by Coastline Products LLC; SMOKING EVERYWHERE® by Smoking Everywhere, Inc.; V2CIGS™ by VMR Products LLC; VAPOR NINE™ by VaporNine LLC; VAPOR4LIFE® by Vapor 4 Life, Inc.; VEPPO™ by E-CigaretteDirect, LLC; VUSE® by R. J. Reynolds Vapor Company; Mistic Menthol product by Mistic Ecigs; and the Vype product by CN Creative Ltd. Yet other electrically powered aerosol delivery devices, and in particular those devices that have been characterized as so-called electronic cigarettes, have been marketed under the tradenames COOLER VISIONS™; DIRECT E-CIG™; DRAGONFLY™; EMIST™; EVERSMOKE™; GAMUCCI®; HYBRID FLAME™; KNIGHT STICKS™; ROYAL BLUES™; SMOKETIP®; SOUTH BEACH SMOKE™.
Additional manufacturers, designers, and/or assignees of components and related technologies that may be employed in aerosol delivery device include Shenzhen Jieshibo Technology of Shenzhen, China; Shenzhen First Union Technology of Shenzhen City, China; Safe Cig of Los Angeles, Calif.; Janty Asia Company of the Philippines; Joyetech Changzhou Electronics of Shenzhen, China; SIS Resources; B2B International Holdings of Dover, Del.; Evolv LLC of OH; Montrade of Bologna, Italy; Shenzhen Bauway Technology of Shenzhen, China; Global Vapor Trademarks Inc. of Pompano Beach, Fla.; Vapor Corp. of Fort Lauderdale, Fla.; Nemtra GMBH of Raschau-Markersbach, Germany, Perrigo L. Co. of Allegan, Mich.; Needs Co., Ltd.; Smokefree Innotec of Las Vegas, Nev.; McNeil AB of Helsingborg, Sweden; Chong Corp; Alexza Pharmaceuticals of Mountain View, Calif.; BLEC, LLC of Charlotte, N.C.; Gaitrend Sarl of Rohrbach-les-Bitche, France; FeelLife Bioscience International of Shenzhen, China; Vishay Electronic BMGH of Selb, Germany; Shenzhen Smaco Technology Ltd. of Shenzhen, China; Vapor Systems International of Boca Raton, Fla.; Exonoid Medical Devices of Israel; Shenzhen Nowotech Electronic of Shenzhen, China; Minilogic Device Corporation of Hong Kong, China; Shenzhen Kontle Electronics of Shenzhen, China, and Fuma International, LLC of Medina, Ohio, and 21st Century Smoke of Beloit, Wis.
The aerosolized compounds delivered from such devices can be evaluated using time of flight mass spectrometry as generally described above. TOF MS instruments are particularly useful in ongoing studies to continuously characterize compounds in sequential puffs of smoke/vapor produced from smoking articles/electronic cigarettes in real time. However, the signal to noise ratio for the analysis of trace amounts of certain compounds found in cigarette smoke and/or electronic cigarette vapor is often relatively low using traditional MS instruments. Accordingly, modifications to traditional MS instruments to allow for enhanced sensitivity for detection of a range of compounds would be desirable.